Ballpoint pen



FIG. 1 is a top view of a ballpoint pen of the present invention;

FIG. 2 is a front view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a right side view thereof; and,

FIG. 6 is a bottom view thereof.

The broken lines in FIGS. 3 and 5 are included to show a feature under the clip that forms no part of the claimed design. 

The ornamental design for a ballpoint pen, as shown and described. 